Final answer:
The politician's support has increased by 27 percentage points (absolute change) and approximately 87.10% (relative change).
Step-by-step explanation:
To determine the absolute and relative change in a politician's support, we need to calculate the difference between the initial and final percentages.
Absolute Change: The politician's support has increased by 27 percentage points (58 - 31).
Relative Change: The politician's support has increased by approximately 87.10% ((58 - 31)/31 x 100).